Value of serum procalcitonin and C-reactive protein on differential diagnosis of pathogen of pulmonary infection

Objective To investigate the value of procalcitonin and C-reactive protein on distinguishing gram-negative bacteria and gram-positive bacteria in pulmonary infection.Methods Serum PCT and CRP levels were measured and compared in patients with pulmonary infection in RICU.Amorg all the patients,42 cases were infected with gram-negative bacteria,39 cases were infected with gram-positive bacteria,and another 35 cases as a control g oup.Results The PCT levels of gram-negative bacteria were higher than those of gram-positive bacteria and the controls,the PCT levels in patients with gram-positive bacteria were higher than that in the control group (P ＜ 0.05).The CRP levels of the three groups were increased similarly(P ＞ 0.05).Conclusions PCT could be used to distinguish gram-negative bacteria and gram-positive bacteria in pulmonary infection.And the specificity of CRP was low. Key words: Procalcitonin ;  C-reactive protein ;  Gram-negative bacteria ;  Gram-positive bacteria